CA3022885C - Coating of functional parts made of metal - Google Patents
Coating of functional parts made of metal Download PDFInfo
- Publication number
- CA3022885C CA3022885C CA3022885A CA3022885A CA3022885C CA 3022885 C CA3022885 C CA 3022885C CA 3022885 A CA3022885 A CA 3022885A CA 3022885 A CA3022885 A CA 3022885A CA 3022885 C CA3022885 C CA 3022885C
- Authority
- CA
- Canada
- Prior art keywords
- range
- baking plate
- nickel
- layer
- baking
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- A—HUMAN NECESSITIES
- A21—BAKING; EDIBLE DOUGHS
- A21B—BAKERS' OVENS; MACHINES OR EQUIPMENT FOR BAKING
- A21B3/00—Parts or accessories of ovens
- A21B3/13—Baking-tins; Baking forms
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J37/00—Baking; Roasting; Grilling; Frying
- A47J37/10—Frying pans, e.g. frying pans with integrated lids or basting devices
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/1601—Process or apparatus
- C23C18/1633—Process of electroless plating
- C23C18/1646—Characteristics of the product obtained
- C23C18/165—Multilayered product
- C23C18/1653—Two or more layers with at least one layer obtained by electroless plating and one layer obtained by electroplating
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/56—Electroplating: Baths therefor from solutions of alloys
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/56—Electroplating: Baths therefor from solutions of alloys
- C25D3/562—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of iron or nickel or cobalt
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/10—Electroplating with more than one layer of the same or of different metals
- C25D5/12—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium
- C25D5/14—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium two or more layers being of nickel or chromium, e.g. duplex or triplex layers
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/18—Electroplating using modulated, pulsed or reversing current
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/48—After-treatment of electroplated surfaces
- C25D5/50—After-treatment of electroplated surfaces by heat-treatment
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/60—Electroplating characterised by the structure or texture of the layers
- C25D5/605—Surface topography of the layers, e.g. rough, dendritic or nodular layers
- C25D5/611—Smooth layers
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/60—Electroplating characterised by the structure or texture of the layers
- C25D5/623—Porosity of the layers
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/627—Electroplating characterised by the visual appearance of the layers, e.g. colour, brightness or mat appearance
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Mechanical Engineering (AREA)
- Food Science & Technology (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Electroplating Methods And Accessories (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
- Cookers (AREA)
- Coating With Molten Metal (AREA)
Abstract
The invention relates to a coating for metal surfaces of functional parts made of metal, preferably baking trays, and a method for producing a coating of this type, wherein at least one coating (2) with an alloy is galvanically applied to the metal surface (6), wherein the coating has a surface layer (3) consisting of a galvanically applied alloy, containing nickel (Ni), phosphorus (P) and tin (Sn) as a main component, and wherein the surface layer (3) is an alloy layer produced from a galvanic bath via pulse plating, preferably pulse-reverse plating.
Description
COATING OF FUNCTIONAL PARTS MADE OF METAL
Technical Background The invention relates to the coating of metal surfaces of functional parts and in particular the coating of baking plates or metal items for the purpose of baking baked products.
Particularly preferably the invention relates to a baking plate with a baking plate body and a coating arranged thereon. Furthermore the invention relates to a method for producing the coating.
Background Coatings of functional parts with hard coating material are now standard in many different areas of industry. In the case of baking plates, in particular coating with hard chrome has proved successful. The high hardness and temperature resistance as well as the chemically very resistant passivation of the surface yield a combination of properties which have made hard chrome the material of choice in many areas in which these surface properties are important. Examples for this are roller coatings in printing machines, coating of hydraulic pistons and piston rods, coatings of moulds in the plastic and rubber industry and the coating of functional components in the pharmaceutical and food industry. Similarly, the coating of baking plates and baking plate sections for industrial baking machines has also proved advantageous.
However, a galvanic bath which contains hexavalent chromium as active component is used in coating with hard chrome. This hexavalent chromium is an environmental toxin and highly carcinogenic. Consequently, the use of this carcinogenic substance for the manufacture of industrial products is very restricted. For this reason, methods and coatings are sought which do not require the use of chromium VI.
However, the use of trivalent chromium baths is also feasible for a decorative chrome coating. The thicker hard chrome coating required for functional parts cannot be i Date Recue/Date Received 2022-08-02 deposited from chromium-III baths. Furthermore, it should be assumed that the use of the trivalent modification of chromium will also be banned shortly.
Simple nickel alloys such as nickel phosphorus are state of the art and can be deposited without an external current or galvanically. Compared to hard chromium coatings however these layers do not have a sufficient layer hardness. In addition, nowhere near the passivity of a hard chrome layer can be achieved with nickel phosphorus layers.
The literature also describes coatings with a nickel alloy having a content of cobalt and phosphorus. However, the content of cobalt which could be dissolved into the wafer sheets from the coating is questionable under the food regulations and is not permitted in some countries.
Summary It is thus an object of the present invention to provide a coating for metal surfaces and in particular for baking plates or other metal surfaces which come into contact with dough at elevated temperature, which have the required properties and are safe in terms of food regulations and technology. Requirements for the new coating lie in the areas of mechanical wear resistance, corrosion resistance, thermal resistance, food licensing, low contamination behaviour and positive baking behaviour, work and environmental safety, reasonable costs, security of supply and similar.
The invention further has the object to provide a coating for functional parts made of metal and in particular for baking plates or metal items for the purpose of baking baked products in which the use of chromium, chromium compounds or other alloy components or electrolyte components which are questionable in terms of food technology and food regulations is avoided. It is furthermore an aim of the invention to provide a surface which is provided with low roughness and which is safe under the food regulations and largely pore-free. In addition, the surface hardness must be sufficiently high for use in baking machines in order to ensure a sufficiently long life during baking and intermediate cleaning steps. It must be possible to produce the baking plates on a large scale industrially, wherein costs should be low.
Technical Background The invention relates to the coating of metal surfaces of functional parts and in particular the coating of baking plates or metal items for the purpose of baking baked products.
Particularly preferably the invention relates to a baking plate with a baking plate body and a coating arranged thereon. Furthermore the invention relates to a method for producing the coating.
Background Coatings of functional parts with hard coating material are now standard in many different areas of industry. In the case of baking plates, in particular coating with hard chrome has proved successful. The high hardness and temperature resistance as well as the chemically very resistant passivation of the surface yield a combination of properties which have made hard chrome the material of choice in many areas in which these surface properties are important. Examples for this are roller coatings in printing machines, coating of hydraulic pistons and piston rods, coatings of moulds in the plastic and rubber industry and the coating of functional components in the pharmaceutical and food industry. Similarly, the coating of baking plates and baking plate sections for industrial baking machines has also proved advantageous.
However, a galvanic bath which contains hexavalent chromium as active component is used in coating with hard chrome. This hexavalent chromium is an environmental toxin and highly carcinogenic. Consequently, the use of this carcinogenic substance for the manufacture of industrial products is very restricted. For this reason, methods and coatings are sought which do not require the use of chromium VI.
However, the use of trivalent chromium baths is also feasible for a decorative chrome coating. The thicker hard chrome coating required for functional parts cannot be i Date Recue/Date Received 2022-08-02 deposited from chromium-III baths. Furthermore, it should be assumed that the use of the trivalent modification of chromium will also be banned shortly.
Simple nickel alloys such as nickel phosphorus are state of the art and can be deposited without an external current or galvanically. Compared to hard chromium coatings however these layers do not have a sufficient layer hardness. In addition, nowhere near the passivity of a hard chrome layer can be achieved with nickel phosphorus layers.
The literature also describes coatings with a nickel alloy having a content of cobalt and phosphorus. However, the content of cobalt which could be dissolved into the wafer sheets from the coating is questionable under the food regulations and is not permitted in some countries.
Summary It is thus an object of the present invention to provide a coating for metal surfaces and in particular for baking plates or other metal surfaces which come into contact with dough at elevated temperature, which have the required properties and are safe in terms of food regulations and technology. Requirements for the new coating lie in the areas of mechanical wear resistance, corrosion resistance, thermal resistance, food licensing, low contamination behaviour and positive baking behaviour, work and environmental safety, reasonable costs, security of supply and similar.
The invention further has the object to provide a coating for functional parts made of metal and in particular for baking plates or metal items for the purpose of baking baked products in which the use of chromium, chromium compounds or other alloy components or electrolyte components which are questionable in terms of food technology and food regulations is avoided. It is furthermore an aim of the invention to provide a surface which is provided with low roughness and which is safe under the food regulations and largely pore-free. In addition, the surface hardness must be sufficiently high for use in baking machines in order to ensure a sufficiently long life during baking and intermediate cleaning steps. It must be possible to produce the baking plates on a large scale industrially, wherein costs should be low.
2 Date Recue/Date Received 2022-08-02 It is furthermore the object of the invention to provide a coating for functional parts made of metal and in particular for baking plates or metal items for the food industry, preferably for the purpose of baking baked products, wherein the transfer of coating components, in particular nickel into the food is substantially prevented. In particular, it is the object of the invention to provide a coating which meets the requirements and the provisions in the area of the food industry.
The invention also comprises coatings for functional parts made of metal, which can generally be used in food technology and in other technologies, where the advantages achievable according to the invention are desired.
Optionally it is provided that the coating comprises a surface layer which consists of an alloy which contains nickel (Ni) and phosphorus (P) as the main component, and furthermore at least one metal from the group molybdenum (Mo) and tin (Sn).
According to a further feature, it is provided that the surface layer contains P in the range of Ito 15 wt.% and Mo up to 10 wt.% and/or Sn up to 10 wt.% and the remainder to 100 wt.% nickel.
According to a further feature, it is provided that the alloy contains 0.05 to 10.0 wt.% Sn and/or 0.01 to 10.0 wt.% Mo and Ito 15 wt.% phosphorus and nickel to 100 wt.%
and that the surface layer is an alloy layer obtained by galvanic deposition, preferably pulsed deposition, particularly preferably inverse pulsed deposition from a galvanic bath.
According to a further feature, it is provided that the surface layer has a roughness, the Ra value of which is less than 5 pm, preferably less than 3 pm and particularly preferably less than 2 pm.
According to a further feature, it is provided that the layer thickness of the surface layer is at least 5 pm, preferably between 10 pm and 50 pm.
The invention also comprises coatings for functional parts made of metal, which can generally be used in food technology and in other technologies, where the advantages achievable according to the invention are desired.
Optionally it is provided that the coating comprises a surface layer which consists of an alloy which contains nickel (Ni) and phosphorus (P) as the main component, and furthermore at least one metal from the group molybdenum (Mo) and tin (Sn).
According to a further feature, it is provided that the surface layer contains P in the range of Ito 15 wt.% and Mo up to 10 wt.% and/or Sn up to 10 wt.% and the remainder to 100 wt.% nickel.
According to a further feature, it is provided that the alloy contains 0.05 to 10.0 wt.% Sn and/or 0.01 to 10.0 wt.% Mo and Ito 15 wt.% phosphorus and nickel to 100 wt.%
and that the surface layer is an alloy layer obtained by galvanic deposition, preferably pulsed deposition, particularly preferably inverse pulsed deposition from a galvanic bath.
According to a further feature, it is provided that the surface layer has a roughness, the Ra value of which is less than 5 pm, preferably less than 3 pm and particularly preferably less than 2 pm.
According to a further feature, it is provided that the layer thickness of the surface layer is at least 5 pm, preferably between 10 pm and 50 pm.
3 Date Recue/Date Received 2022-08-02 According to a further feature, it is provided that one or more underlayers are disposed between surface layer and metal surface.
According to a further feature, it is provided that the underlayers are nickel layers applied electrolytically or without external current.
According to a further feature, it is provided that the hardness gradient of the underlayers as far as the surface layer is configured to be ascending.
According to a further feature, it is provided that the underlayers are double-layer and a first underlayer nearest the metal surface consists of a semi-gloss nickel layer or copper and a second underlayer consists of a gloss nickel layer.
Baking plates according to the invention have the coating described, wherein the coated metal surface is the baking surface of a baking plate, in particular a baking plate for the industrial manufacture of crispy brittle wafer sheets, waffles and hollow wafers as well as baked products of all kinds. In this case it is provided that the baking surface is formed with a moulding forming the baking mould and engraving.
According to a further feature, it is provided that the coated baking plate is annealed at temperatures between 150 C and 400 C.
According to a further feature, it is provided that the baking plate body of the baking plate consists of cast iron, steel or aluminium.
The invention is described hereinafter with reference to the coating of a baking surface of a baking plate, wherein the term baking plate is to be understood in the widest sense.
The baking plates can be configured with smooth, flat surfaces as baking surface. Such baking surfaces can also be provided with an engraving or surface design to mould the desired baked product made of dough accordingly. The baking plate can however, as a functional part made of metal, also have a roller form or the form of a cone around which the dough to be baked is wound or in the case of the roller, pressed into the soft dough.
According to a further feature, it is provided that the underlayers are nickel layers applied electrolytically or without external current.
According to a further feature, it is provided that the hardness gradient of the underlayers as far as the surface layer is configured to be ascending.
According to a further feature, it is provided that the underlayers are double-layer and a first underlayer nearest the metal surface consists of a semi-gloss nickel layer or copper and a second underlayer consists of a gloss nickel layer.
Baking plates according to the invention have the coating described, wherein the coated metal surface is the baking surface of a baking plate, in particular a baking plate for the industrial manufacture of crispy brittle wafer sheets, waffles and hollow wafers as well as baked products of all kinds. In this case it is provided that the baking surface is formed with a moulding forming the baking mould and engraving.
According to a further feature, it is provided that the coated baking plate is annealed at temperatures between 150 C and 400 C.
According to a further feature, it is provided that the baking plate body of the baking plate consists of cast iron, steel or aluminium.
The invention is described hereinafter with reference to the coating of a baking surface of a baking plate, wherein the term baking plate is to be understood in the widest sense.
The baking plates can be configured with smooth, flat surfaces as baking surface. Such baking surfaces can also be provided with an engraving or surface design to mould the desired baked product made of dough accordingly. The baking plate can however, as a functional part made of metal, also have a roller form or the form of a cone around which the dough to be baked is wound or in the case of the roller, pressed into the soft dough.
4 Date Recue/Date Received 2022-08-02 In the broadest sense, baking plates can be understood as any metal object with a surface which comes in contact with baked products. All these baking plates or functional parts have in common that they must be abrasion-proof even when frequent cleaning steps are required. Furthermore, the baked products must be easy to release from the surface free from residue. The baking plates can also be multipart, wherein a plurality of baking plate parts are arranged in a carrier frame.
The metal body to be coated is also designated hereinafter as baking plate body.
Usually the baking plate body consists of a solid plate made of steel or cast iron, possibly also made of aluminium or aluminium alloys and is formed to be so solid that during the baking process the necessary hear can be stored or released. In this case, the baking plate as a whole can be provided with a baking surface on one of the flat sides as is required for large wafer baking plates to produce crispy brittle wafer plates.
However, the baking plate body can also have smaller delimited baking surfaces if, for example, a plurality of separate pieces of the baked product are to be produced on a baking plate as can be the case with waffles.
Brief Description of the Drawings Fig. 1 shows a schematic cross-section through a functional part with coating.
Fig. 2 to Fig. 5 show scanning electron microscope photographs of cross-sections of surfaces of the coatings according to the examples.
Detailed Description The invention now is explained further for example with reference to Fig. 1 without wishing to thereby restrict the invention. The layer thicknesses are not shown to scale.
As shown in Fig. 1, the coating 2 according to the invention lies on the metal body (baking plate body 1). The coating 2 comprises either entirely or on its surface the galvanically applied alloy according to the invention which is hereinafter also called surface layer 3. Underlayers of various materials can also be applied under the surface Date Recue/Date Received 2022-08-02 layer 3, as is shown in the figure. Preferably a first underlayer 4 of, for example, semi-gloss nickel is deposited on the baking plate body 1 and then a gloss nickel layer is provided thereon. The surface layer 3 which exhibits the surface properties is then deposited on this gloss nickel layer 5.
The arrangement of one or more underlayers offers the advantage that the hardness gradient runs in an ascending manner from the material of the baking plate body 1 to the surface layer 3. This results in a substantially reduced tendency of the surface layer 3 to detach.
The underlayers can also be omitted if the surface layer according to the invention is deposited directly on the metal surface of the functional parts. It also lies within the scope of the invention to apply only one nickel underlayer. The nickel underlayers can be deposited both without an external current and also electrolytically, in a pulsed or non-pulsed manner. In the case of deposition without an external current, a phosphorus content can also be provided in the nickel underlayer. In one embodiment, a copper layer can be applied as a first underlayer 4, preferably up to 10 pm layer thickness, which is then followed by a nickel underlayer as carrier for the surface layer.
The surface layer with the alloy coating preferably has a layer thickness of at least 5 pm, preferably between 10 pm and 50 pm. A higher layer thickness can be provided in some cases but this brings with it the difficulty of the dimensional tolerance of the finished baking plate. A layer thickness of less than 5 pm is prone to wear and can only be used to a limited extent for functional parts made of metal. For example, a layer thickness of less than 5 pm can be advantageous for surfaces which are difficult to coat such as hollow wafer geometries if the mechanical loading is kept low. In this case, it should be noted that when coating an engraved surface, the deposition on the different surface patterns can vary. Thus, engraving tips are more thickly coated and the groove bases are less thickly coated. It is important that the ratio of the layer thicknesses does not vary too substantially.
Date Recue/Date Received 2022-08-02 The surface layer should have an arithmetic mean roughness Ra of less than 5 pm, preferably less than 3 pm and further preferably less than 2 pm. The Ra value is measured according to DIN EN 150 4288: 1998-04. The lower the roughness, the better the release property for the baked product and the lower the risk of contamination.
The surface coating used according to the invention and proving to be advantageous is a nickel phosphorus alloy which contains 1 to 15 wt.% of phosphorus and optionally 0.01 to 10 wt.% of molybdenum or 0.05 to 10 wt.% of tin or both tin and molybdenum within the given limits. The remainder to 100 wt.% is nickel.
Preferably two nickel layers are disposed between surface layer and baking plate body, namely a pulsed first nickel layer with a nickel matt layer and a pulsed gloss nickel layer thereon. The increasing hardness of the layers offers the advantage that the binding of the surface layer is increased and it is thus ensured that the surface layer cannot detach from the baking plate.
The surface designs provided on the baking plate body and in particular engraving can be configured according to the prior art and require no modification compared to this.
After the coating of the baking plate, it is advantageous to provide an annealing at temperatures between 150 C and 400 C. For baking plates which during operation run continuously in a higher temperature range from about 180 C to 220 C, the annealing can also be carried out during the ongoing operation so that a separate annealing step is not required.
The electrolyte for deposition of the surface coating preferably comprises a selection at least from the following salts and acids:
a) nickel sulphate hexahyd rate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
c) tin (IV) chloride hydrate in the range of 1 - 40 g/I
d) tin (II) sulphate in the range of 1 - 30 g/I
Date Recue/Date Received 2022-08-02 e) tin (II) chloride dihydrate in the range of 1 - 40 WI
f) odium molybdate dihydrate in the range of 1 - 30 g/I
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
k) phosphoric acid in the range of 1 - 5 g/I
I) sodium hypophosphite in the range of 5 - 40 g/I
m)sodium gluconate in the range of 40 - 90 WI
n) potassium sodium tartrate in the range of 10 - 50 g/I
According to the invention, it is provided that the metal surface is coated at least in sections with a surface layer of NiMoP or NiSnP or NiSnMoP alloy by galvanic deposition, preferably in a pulsed method and particularly preferably in an inverse pulsed method from a galvanic bath.
According to a further feature, it is provided that the pulsed deposition of the coating from an electrolyte bath is carried out with the following parameter ranges:
a unipolar pulse sequence with pulse current density 0.5-15 A/dm2 cathodic pulse time 5- 100 ms off time 0.5 - 25 ms According to a further feature, it is provided that a unipolar pulse sequence with base current and pulse pause as follows is used to produce the layer: pulse current density from 0.5 to 15 A/dm2, base current density from 0.1 to 8 A/dm2, cathodic pulse time from to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
According to a further feature, it is provided that a bipolar pulse with pulse pause as follows is used to produce the layer: cathodic pulse current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 Date Recue/Date Received 2022-08-02 with a pulse time from 5 to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
According to a further feature, it is provided that a bipolar pulse with a base current as follows is used to produce the layer: cathodic pulse current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, cathodic base current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the anodic pulse current.
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
- nickel chloride hexahydrate in the range of 5 - 50 g/I
- tin (IV) chloride hydrate in the range of 1 - 40 g/I
- boric acid in the range of 25 - 45 g/I
- phosphorous acid in the range of 1 - 25 g/I
- phosphoric acid in the range of 1 - 5 g/I
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
- nickel chloride hexahydrate in the range of 5 - 50 g/I
- molybdatophosphoric acid in the range of 1 - 30 g/I
- sodium citrate in the range of 1 - 90 g/I
- boric acid in the range of 25 - 45 g/I
- phosphorous acid in the range of 1 - 25 g/I
- phosphoric acid in the range of 1 - 5 g/I
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
Date Recue/Date Received 2022-08-02 - nickel chloride hexahydrate in the range of 5 - 50 g/I
- sodium molybdate dihydrate in the range of 1 - 30 g/I
- sodium citrate in the range of 1 - 90 WI
- boric acid in the range of 25 - 45 g/I
- sodium hypophosphite in the range of 5 - 40 g/I
wherein the electrolyte bath additionally can contain the following constituents:
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/I
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
- nickel chloride hexahydrate in the range of 5 - 50 g/I
- tin (II) sulphate in the range of 1 - 30 g/I
- tin (II) chloride dihydrate in the range of 1 - 40 WI
- sodium molybdate dihydrate in the range of 1 - 30 g/I
- boric acid in the range of 25 - 45 g/I
- phosphorous acid in the range of 1 - 25 g/I
- sodium gluconate in the range of 40 - 90 WI
- potassium sodium tartrate in the range of 10 - 50 g/I
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
- nickel chloride hexahydrate in the range of 5 - 50 g/I
- tin (II) sulphate in the range of 1 - 30 g/I
- tin (II) chloride dihydrate in the range of 1 - 40 g/I
- sodium molybdate dihydrate in the range of 1 - 30 g/I
- boric acid in the range of 25 - 45 g/I
- phosphorous acid in the range of 1 - 25 g/I
- sodium gluconate in the range of 40 - 90 g/I
Date Recue/Date Received 2022-08-02 - potassium sodium tartrate in the range of 10 - 50 g/I
According to a further feature, it is provided that the pH is 1.0 to 5.0 and the bath temperature is 25 C to 75 C.
The electrolyte has a pH of 1.0 to 5.5 and a temperature of 25 to 75 C.
In order to produce the alloy layer in one of these electrolytes, a direct current can be used, preferably with a current density of 0.5 to 15 A/dm2.
In order to produce the layer, preferably a unipolar pulse sequence can be used as follows: pulse current density from 0.5 to 15 Aklm2, cathodic pulse time from
The metal body to be coated is also designated hereinafter as baking plate body.
Usually the baking plate body consists of a solid plate made of steel or cast iron, possibly also made of aluminium or aluminium alloys and is formed to be so solid that during the baking process the necessary hear can be stored or released. In this case, the baking plate as a whole can be provided with a baking surface on one of the flat sides as is required for large wafer baking plates to produce crispy brittle wafer plates.
However, the baking plate body can also have smaller delimited baking surfaces if, for example, a plurality of separate pieces of the baked product are to be produced on a baking plate as can be the case with waffles.
Brief Description of the Drawings Fig. 1 shows a schematic cross-section through a functional part with coating.
Fig. 2 to Fig. 5 show scanning electron microscope photographs of cross-sections of surfaces of the coatings according to the examples.
Detailed Description The invention now is explained further for example with reference to Fig. 1 without wishing to thereby restrict the invention. The layer thicknesses are not shown to scale.
As shown in Fig. 1, the coating 2 according to the invention lies on the metal body (baking plate body 1). The coating 2 comprises either entirely or on its surface the galvanically applied alloy according to the invention which is hereinafter also called surface layer 3. Underlayers of various materials can also be applied under the surface Date Recue/Date Received 2022-08-02 layer 3, as is shown in the figure. Preferably a first underlayer 4 of, for example, semi-gloss nickel is deposited on the baking plate body 1 and then a gloss nickel layer is provided thereon. The surface layer 3 which exhibits the surface properties is then deposited on this gloss nickel layer 5.
The arrangement of one or more underlayers offers the advantage that the hardness gradient runs in an ascending manner from the material of the baking plate body 1 to the surface layer 3. This results in a substantially reduced tendency of the surface layer 3 to detach.
The underlayers can also be omitted if the surface layer according to the invention is deposited directly on the metal surface of the functional parts. It also lies within the scope of the invention to apply only one nickel underlayer. The nickel underlayers can be deposited both without an external current and also electrolytically, in a pulsed or non-pulsed manner. In the case of deposition without an external current, a phosphorus content can also be provided in the nickel underlayer. In one embodiment, a copper layer can be applied as a first underlayer 4, preferably up to 10 pm layer thickness, which is then followed by a nickel underlayer as carrier for the surface layer.
The surface layer with the alloy coating preferably has a layer thickness of at least 5 pm, preferably between 10 pm and 50 pm. A higher layer thickness can be provided in some cases but this brings with it the difficulty of the dimensional tolerance of the finished baking plate. A layer thickness of less than 5 pm is prone to wear and can only be used to a limited extent for functional parts made of metal. For example, a layer thickness of less than 5 pm can be advantageous for surfaces which are difficult to coat such as hollow wafer geometries if the mechanical loading is kept low. In this case, it should be noted that when coating an engraved surface, the deposition on the different surface patterns can vary. Thus, engraving tips are more thickly coated and the groove bases are less thickly coated. It is important that the ratio of the layer thicknesses does not vary too substantially.
Date Recue/Date Received 2022-08-02 The surface layer should have an arithmetic mean roughness Ra of less than 5 pm, preferably less than 3 pm and further preferably less than 2 pm. The Ra value is measured according to DIN EN 150 4288: 1998-04. The lower the roughness, the better the release property for the baked product and the lower the risk of contamination.
The surface coating used according to the invention and proving to be advantageous is a nickel phosphorus alloy which contains 1 to 15 wt.% of phosphorus and optionally 0.01 to 10 wt.% of molybdenum or 0.05 to 10 wt.% of tin or both tin and molybdenum within the given limits. The remainder to 100 wt.% is nickel.
Preferably two nickel layers are disposed between surface layer and baking plate body, namely a pulsed first nickel layer with a nickel matt layer and a pulsed gloss nickel layer thereon. The increasing hardness of the layers offers the advantage that the binding of the surface layer is increased and it is thus ensured that the surface layer cannot detach from the baking plate.
The surface designs provided on the baking plate body and in particular engraving can be configured according to the prior art and require no modification compared to this.
After the coating of the baking plate, it is advantageous to provide an annealing at temperatures between 150 C and 400 C. For baking plates which during operation run continuously in a higher temperature range from about 180 C to 220 C, the annealing can also be carried out during the ongoing operation so that a separate annealing step is not required.
The electrolyte for deposition of the surface coating preferably comprises a selection at least from the following salts and acids:
a) nickel sulphate hexahyd rate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
c) tin (IV) chloride hydrate in the range of 1 - 40 g/I
d) tin (II) sulphate in the range of 1 - 30 g/I
Date Recue/Date Received 2022-08-02 e) tin (II) chloride dihydrate in the range of 1 - 40 WI
f) odium molybdate dihydrate in the range of 1 - 30 g/I
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
k) phosphoric acid in the range of 1 - 5 g/I
I) sodium hypophosphite in the range of 5 - 40 g/I
m)sodium gluconate in the range of 40 - 90 WI
n) potassium sodium tartrate in the range of 10 - 50 g/I
According to the invention, it is provided that the metal surface is coated at least in sections with a surface layer of NiMoP or NiSnP or NiSnMoP alloy by galvanic deposition, preferably in a pulsed method and particularly preferably in an inverse pulsed method from a galvanic bath.
According to a further feature, it is provided that the pulsed deposition of the coating from an electrolyte bath is carried out with the following parameter ranges:
a unipolar pulse sequence with pulse current density 0.5-15 A/dm2 cathodic pulse time 5- 100 ms off time 0.5 - 25 ms According to a further feature, it is provided that a unipolar pulse sequence with base current and pulse pause as follows is used to produce the layer: pulse current density from 0.5 to 15 A/dm2, base current density from 0.1 to 8 A/dm2, cathodic pulse time from to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
According to a further feature, it is provided that a bipolar pulse with pulse pause as follows is used to produce the layer: cathodic pulse current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 Date Recue/Date Received 2022-08-02 with a pulse time from 5 to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
According to a further feature, it is provided that a bipolar pulse with a base current as follows is used to produce the layer: cathodic pulse current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, cathodic base current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the anodic pulse current.
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
- nickel chloride hexahydrate in the range of 5 - 50 g/I
- tin (IV) chloride hydrate in the range of 1 - 40 g/I
- boric acid in the range of 25 - 45 g/I
- phosphorous acid in the range of 1 - 25 g/I
- phosphoric acid in the range of 1 - 5 g/I
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
- nickel chloride hexahydrate in the range of 5 - 50 g/I
- molybdatophosphoric acid in the range of 1 - 30 g/I
- sodium citrate in the range of 1 - 90 g/I
- boric acid in the range of 25 - 45 g/I
- phosphorous acid in the range of 1 - 25 g/I
- phosphoric acid in the range of 1 - 5 g/I
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
Date Recue/Date Received 2022-08-02 - nickel chloride hexahydrate in the range of 5 - 50 g/I
- sodium molybdate dihydrate in the range of 1 - 30 g/I
- sodium citrate in the range of 1 - 90 WI
- boric acid in the range of 25 - 45 g/I
- sodium hypophosphite in the range of 5 - 40 g/I
wherein the electrolyte bath additionally can contain the following constituents:
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/I
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
- nickel chloride hexahydrate in the range of 5 - 50 g/I
- tin (II) sulphate in the range of 1 - 30 g/I
- tin (II) chloride dihydrate in the range of 1 - 40 WI
- sodium molybdate dihydrate in the range of 1 - 30 g/I
- boric acid in the range of 25 - 45 g/I
- phosphorous acid in the range of 1 - 25 g/I
- sodium gluconate in the range of 40 - 90 WI
- potassium sodium tartrate in the range of 10 - 50 g/I
According to a further feature, it is provided that the electrolyte bath contains the following constituents:
- nickel sulphate hexahydrate in the range of 250 - 700 g/I
- nickel chloride hexahydrate in the range of 5 - 50 g/I
- tin (II) sulphate in the range of 1 - 30 g/I
- tin (II) chloride dihydrate in the range of 1 - 40 g/I
- sodium molybdate dihydrate in the range of 1 - 30 g/I
- boric acid in the range of 25 - 45 g/I
- phosphorous acid in the range of 1 - 25 g/I
- sodium gluconate in the range of 40 - 90 g/I
Date Recue/Date Received 2022-08-02 - potassium sodium tartrate in the range of 10 - 50 g/I
According to a further feature, it is provided that the pH is 1.0 to 5.0 and the bath temperature is 25 C to 75 C.
The electrolyte has a pH of 1.0 to 5.5 and a temperature of 25 to 75 C.
In order to produce the alloy layer in one of these electrolytes, a direct current can be used, preferably with a current density of 0.5 to 15 A/dm2.
In order to produce the layer, preferably a unipolar pulse sequence can be used as follows: pulse current density from 0.5 to 15 Aklm2, cathodic pulse time from
5 to 100 ms, off time from 0 to 25 ms.
Furthermore, a unipolar pulse sequence with base current and pulse pause as follows can be used as follows to produce the layer: pulse current density from 0.5 to 15 A/dm2, base current density from 0.1 to 8 Aklm2, cathodic pulse time from 5 to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
Furthermore a bipolar pulse with pulse pause can be used as follows to produce the layer: cathodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, pulse pause from 0 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
Furthermore a bipolar pulse with a base current can be used as follows to produce the layer: cathodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, cathodic base current density from 0.1 to 8 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the anodic pulse current.
Date Recue/Date Received 2022-08-02 The invention is explained in detail in the following examples without restricting the invention to the examples.
Example 1: layer comprising nickel, tin and phosphorus The following electrolyte composition was proposed:
- 40 g/I boric acid - 510 g/I nickel sulphate hexahydrate - 20 g/I nickel chloride hexahydrate - 21 g/I phosphorous acid - 12 g/I tin (IV) chloride hydrate The chemicals are dissolved in order in warm water. After adding and dissolving all the components, the pH is adjusted. The pH is adjusted using 1% sodium hydroxide solution or 50% sulphuric acid.
The pH should lie between 1.1 - 1.8, the optimum is 1.2.
The electrolyte operates at a temperature of 55 - 75 C.
Deposition takes place whilst stirring vigorously (500 rpm).
A nickel-plated steel substrate was used as the substrate.
A unipolar rectangular pulse was used to produce the layer, wherein the mean current density was 4 A/dm2. The cathodic current densities were 3.25 A/dm2 for 15 ms and 6.5 A/dm2 for 5 ms.
The coating time was 60 minutes.
The layers thus produced had the following composition:
nickel 94.5 wt.%, tin 0.5 wt.%, phosphorus 5 wt.%, the alloy elements together gave 100 %.
The layers showed good adhesion, were free from cracks and shiny, layer thicknesses were approximately 10 pm. Annealing at 200 C was carried out for 30 minutes.
Date Recue/Date Received 2022-08-02 Fig. 2 shows a polished cross-section of the layer in a scanning electron microscope photograph and the EDX spectrum. The substrate was cast iron with spherical graphite.
The coating had a thickness of 51.4 pm.
Fig. 3 shows the SEM micrograph of the surface.
Example 2: layer comprising nickel, molybdenum and phosphorus The following electrolyte composition was proposed:
510 g/I nickel sulphate hexahydrate - 20 g/I nickel chloride hexahydrate - 40 g/I boric acid - 21 g/I phosphorous acid - 50 g/I sodium citrate - 13 g/I molybdatophosphoric acid The chemicals are dissolved in order in warm water. After adding and dissolving all the components, the pH is adjusted. The pH is adjusted using 1% sodium hydroxide solution or 50% sulphuric acid.
The pH should lie between 1.2 - 3.0, the optimum is 2.3.
The electrolyte operates at a temperature of 45-55 C.
Deposition takes place whilst stirring moderately vigorously (300 -500 rpm).
A 1 mm thick brass plate having the dimensions 30 mm x 30 mm was used as the substrate.
A unipolar rectangular pulse was used to produce the layer, wherein the mean current density was 3.0 A/dm2. The cathodic current densities were 2.5 and 5.0 A/dm2 for 10 ms, the subsequent pulse pause was 10 ms.
The coating time was one hour.
The layers thus produced had the following composition:
nickel 96.2 wt.%, molybdenum 0.8 wt.% and phosphorus 3 wt.%, the alloy elements together gave 100%.
Date Recue/Date Received 2022-08-02 The layers showed good adhesion, were free from cracks and shiny, layer thicknesses were approximately 10 pm. Annealing at 200 C was carried out for 30 minutes.
Fig. 4 shows the scanning electron micrograph of the surface of the layer and the EDX
spectrum.
Example 3: layer comprising nickel, tin, molybdenum and phosphorus The following electrolyte composition was proposed:
510 g/I nickel sulphate hexahydrate - 20 g/I nickel chloride hexahydrate - 40 g/I boric acid - 21 g/I phosphorous acid - 50 g/I sodium citrate - 13 g/I molybdatophosphoric acid - 12 g/I tin (VI) chloride hydrate The chemicals are dissolved in order in warm water. After adding and dissolving all the components, the pH is adjusted. The pH is adjusted using 1% sodium hydroxide solution or 50% sulphuric acid.
The pH should lie between 1.2 - 3.0, the optimum is 2.3.
The electrolyte operates at a temperature of 55-75 C.
Deposition takes place whilst stirring moderately to vigorously (300 -500 rpm).
A 1 mm thick brass plate having the dimensions 30 mm x 30 mm was used as the substrate.
A bipolar rectangular pulse was used to produce the layer, wherein the mean current density was 2.3 A/dm2. The cathodic current densities were 2.0 and 6.0 A/dm2 for 20 and ms, the anodic current density was 5 A/dm2 for 5 ms, the subsequent pulse pause was 10 ms.
The coating time was one hour.
The layers thus produced had the following composition:
Date Recue/Date Received 2022-08-02 nickel 91.5 wt.%, molybdenum 2 wt.%, tin 0.5 wt.% and phosphorus 6 wt.%, the alloy elements together gave 100 %.
The layers showed good adhesion, were free from cracks and shiny. The layer thickness was approximately 10 pm.
Example 4: layer comprising nickel, molybdenum and phosphorus The following electrolyte composition was proposed:
340 g/I nickel sulphate hexahydrate - 20 g/I nickel chloride hexahydrate - 13.7 g/I sodium hypophosphite - 50 g/I sodium citrate - 2.5 g/I sodium molybdate The chemicals are dissolved in order in warm water. After adding and dissolving all the components, the pH is adjusted. The pH is adjusted using 1% sodium hydroxide solution or 50% sulphuric acid. The pH should lie between 5.0-5.2, the optimum is 5.1.
The electrolyte operates at a temperature of 45-55 C.
Deposition takes place whilst stirring moderately vigorously (300 -500 rpm).
A 1 mm thick brass plate having the dimensions 30 mm x 30 mm was used as the substrate.
A unipolar rectangular pulse was used to produce the layer, wherein the mean current density was 1.6 A/dm2. The cathodic current densities were 1.5 and 2.5 A/dm2 for 10 ms, the subsequent pulse pause was 10 ms.
The coating time was one hour.
The layers thus produced had the following composition:
nickel 90.5 wt.%, molybdenum 5.0 wt.% and phosphorus 4.5 wt.%, the alloy elements together gave 100%.
The layers showed good adhesion, were free from cracks and shiny.
Date Recue/Date Received 2022-08-02 Fig. 5 shows the surface of the layer in a scanning electron micrograph and the EDX
spectrum.
In particular the invention relates to a coating of metal surfaces of functional parts made of metal, preferably baking plates, wherein at least one coating with an alloy is applied galvanically to the metal surface. The functional parts can also be other metal parts which are used to heat food, such as frying pans, grill surfaces, cooking pots and the like. The baking plates are preferably baking plates for the industrial production of wafer products. All these functional parts are subsequently designated as baking plates.
Optionally it is provided that the coating comprises a surface layer which consists of a galvanically applied alloy which contains nickel, phosphorus, and tin as the main component and that the surface layer is an alloy layer obtained by a pulsed deposition, preferably an inverse pulsed deposition from a galvanic bath.
Only be using pulsed deposition, preferably an inverse pulsed deposition, can a coating be obtained on a metal surface which meets the high requirements, in particular in the food area. In particular, a coating is obtained which can be used in the food area, in particular in the baking industry, whilst adhering to the specification and conditions valid there. Optionally due to the properties of the pulsed method, it is also possible to influence or adjust the surface layer in terms of its properties.
Optionally it is provided that the surface layer contains phosphorus in the range of 1 to 15 wt.%, tin up to 10 wt.% and the remainder to 100 wt.% nickel.
Optionally it is provided that the alloy contains 0.05 to 10.0 wt.% tin and 1 to 15 wt.%
phosphorus and nickel to 100 wt.%.
By adding tin and/or phosphorus, the release of nickel from the coating can be reduced, in particular substantially prevented. Only with the coating according to the invention is it possible to meet the high requirements, in particular the high requirements in the food area. Differently configured layers cannot prevent the release of coating components, in Date Recue/Date Received 2022-08-02 particular nickel, and therefore do not meet the high requirements. Optionally it is provided that the phosphorus content in the surface layer lies in the range from 7 to 14%, in particular 9 to 12%. Optionally the release of nickel cannot be sufficiently prevented below a phosphorus content of 9%.
Optionally it is provided that the surface layer additionally contains molybdenum and that the surface layer contains up to 10 wt.% of molybdenum and/or that the alloy contains 0.01 to 10 wt.% of molybdenum.
Since the surface layer also contains molybdenum, the wear resistance of the coating, in particular the hardness of the coating can be increased.
Optionally it is provided that the surface layer has a roughness, the Ra value of which is less than 5 pm, preferably less than 3 pm and particularly preferably less than 2 pm.
Optionally it is provided that the layer thickness of the surface layer is at least 5 pm preferably between 10 pm and 50 pm.
Optionally it is provided that one or more underlayers are disposed between surface layer and metal surface.
Optionally it is provided that the underlayers are nickel layers applied electrolytically or without external current.
Optionally it is provided that the hardness gradient of the underlayers as far as the surface layer is configured to be ascending.
Optionally it is provided that the underlayers are double-layer and a first underlayer nearest the metal surface consists of a semi-gloss nickel layer or copper and a second underlayer consists of a gloss nickel layer.
Date Recue/Date Received 2022-08-02 In particular, the invention relates to a baking plate having a coating according to the invention, wherein the coated metal surface is the baking surface of a baking plate, in particular a baking plate for the industrial manufacture of crispy brittle wafer sheets, waffles and hollow wafers as well as baked products of all kinds.
Optionally it is provided that the baking surface is formed with a moulding forming the baking mould and engraving.
Optionally it is provided that the coated baking plate is annealed at temperatures between 150 C and 700 C, preferably between 200 and 400 C, particularly preferably at 300 C and that the coated baking plate is annealed for a duration in the range from one hour to six hours, preferably up to four hours.
Optionally it is provided that the baking plate body of the baking plate consists of cast iron, steel, aluminium, aluminium alloys or copper and alloys thereof such as brass.
In particular, the invention relates to a method for the coating metal surfaces, in particular baking plates made of cast iron, steel, aluminium or aluminium alloys or copper and alloys thereof such as brass.
Optionally it is provided that the metal surface is coated at least in sections with a surface layer of NiSnP or NiSnMoP alloy in a galvanic method, preferably pulsed method and particularly preferably in an inverse pulsed method from a galvanic bath.
Optionally it is provided that the pulsed deposition of the coating from an electrolyte bath is carried out with the following parameter ranges:
a unipolar pulse sequence with pulse current density 0.5-15 A/dm2 cathodic pulse time 5- 100 ms off time 0.5 - 25 ms Optionally it is provided that a unipolar pulse sequence with base current and pulse pause as follows is used to produce the layer: pulse current density from 0.5 to 15 Date Recue/Date Received 2022-08-02 A/dm2, base current density from 0.1 to 8 A/dm2, cathodic pulse time from 5 to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
Optionally it is provided that a bipolar pulse with pulse pause as follows is used to produce the layer: cathodic pulse current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
Optionally it is provided that a bipolar pulse with a base current as follows is used to produce the layer: cathodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, cathodic base current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the anodic pulse current.
Optionally it is provided that the electrolyte bath contains salts and acids selected from the following group:
a) nickel sulphate hexahyd rate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
c) tin (IV) chloride hydrate in the range of 1 - 40 g/I
d) tin (II) sulphate in the range of 1 - 30 g/I
e) tin (II) chloride dihydrate in the range of 1 - 40 WI
f) sodium molybdate dihydrate in the range of 1 - 30 g/I
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
k) phosphoric acid in the range of 1 - 5 g/I
I) sodium hypophosphite in the range of 5 -40 g/I
m)sodium gluconate in the range of 40 - 90 g/I
Date Recue/Date Received 2022-08-02 n) potassium sodium tartrate in the range of 10 - 50 g/I
Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
c) tin (IV) chloride hydrate in the range of 1 - 40 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
k) phosphoric acid in the range of 1 - 5 g/I
Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/1 i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
k) phosphoric acid in the range of 1 - 5 g/1 Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
f) sodium molybdate dihydrate in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/I
i) boric acid in the range of 25 - 45 g/I
1) sodium hypophosphite in the range of 5 - 40 g/I
Optionally it is provided that the electrolyte bath additionally contains the following constituents:
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 WI
Date Recue/Date Received 2022-08-02 Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
d) tin (II) sulphate in the range of 1 - 30 g/I
e) tin (II) chloride dihydrate in the range of 1 - 40 g/I
f) sodium molybdate dihydrate in the range of 1 - 30 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
m)sodium gluconate in the range of 40 - 90 WI
n) potassium sodium tartrate in the range of 10 - 50 g/I
Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
d) tin (II) sulphate in the range of 1 - 30 g/I
e) tin (II) chloride dihydrate in the range of 1 - 40 WI
f) sodium molybdate dihydrate in the range of 1 - 30 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
m)sodium gluconate in the range of 40 - 90 WI
n) potassium sodium tartrate in the range of 10 - 50 g/I
Optionally it is provided that the pH of the electrolyte bath is 1.0 to 5.5 and the bath temperature of the electrolyte bath is 25 C to 75 C.
Optionally it is provided that that the pH of the electrolyte bath is 1.0 to 1.5, in particular 1.1, 1.2 and 1.3. Optionally it is provided that the bath temperature is 55 C
to 65 C, in particular 60 C.
Optionally it is provided that the method comprises the following further steps:
- washing the coated metal surface, - optionally drying the coated metal surface, Date Recue/Date Received 2022-08-02 - annealing the coated metal surface for a time in the range from one hour to six hours, in particular four hours, at a temperature in the range of 100 C and C, preferably between 200 C and 400 C, particularly preferably 300 C.
Optionally it is provided that a coating having the hardness in the range of 400 Vickers and 800 Vickers, in particular 600 Vickers, is produced.
Optionally it is provided that the hardness of the coating is increased by annealing to 700 Vickers to 1000 Vickers, in particular 900 Vickers.
The hardness of the coating can be adjusted by annealing. Before the annealing step the coating possibly has a hardness of 400 to 800 Vickers, in particular 600 Vickers. The hardness of the coating can be increased by annealing to 700 Vickers to 1000 Vickers, in particular 900 Vickers. The hardness of the coating can be adjusted by the annealing time and also the annealing temperature. In particular, a lower hardness of the coating can be achieved by a short annealing time and/or by a low annealing temperature. The annealing can be carried out in an annealing device, in particular an annealing furnace.
The term annealing should be understood in this context as a general heating of a material over a longer time interval. The annealing process can be carried out in air or also in an inert furnace atmosphere.
Date Recue/Date Received 2022-08-02
Furthermore, a unipolar pulse sequence with base current and pulse pause as follows can be used as follows to produce the layer: pulse current density from 0.5 to 15 A/dm2, base current density from 0.1 to 8 Aklm2, cathodic pulse time from 5 to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
Furthermore a bipolar pulse with pulse pause can be used as follows to produce the layer: cathodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, pulse pause from 0 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
Furthermore a bipolar pulse with a base current can be used as follows to produce the layer: cathodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, cathodic base current density from 0.1 to 8 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the anodic pulse current.
Date Recue/Date Received 2022-08-02 The invention is explained in detail in the following examples without restricting the invention to the examples.
Example 1: layer comprising nickel, tin and phosphorus The following electrolyte composition was proposed:
- 40 g/I boric acid - 510 g/I nickel sulphate hexahydrate - 20 g/I nickel chloride hexahydrate - 21 g/I phosphorous acid - 12 g/I tin (IV) chloride hydrate The chemicals are dissolved in order in warm water. After adding and dissolving all the components, the pH is adjusted. The pH is adjusted using 1% sodium hydroxide solution or 50% sulphuric acid.
The pH should lie between 1.1 - 1.8, the optimum is 1.2.
The electrolyte operates at a temperature of 55 - 75 C.
Deposition takes place whilst stirring vigorously (500 rpm).
A nickel-plated steel substrate was used as the substrate.
A unipolar rectangular pulse was used to produce the layer, wherein the mean current density was 4 A/dm2. The cathodic current densities were 3.25 A/dm2 for 15 ms and 6.5 A/dm2 for 5 ms.
The coating time was 60 minutes.
The layers thus produced had the following composition:
nickel 94.5 wt.%, tin 0.5 wt.%, phosphorus 5 wt.%, the alloy elements together gave 100 %.
The layers showed good adhesion, were free from cracks and shiny, layer thicknesses were approximately 10 pm. Annealing at 200 C was carried out for 30 minutes.
Date Recue/Date Received 2022-08-02 Fig. 2 shows a polished cross-section of the layer in a scanning electron microscope photograph and the EDX spectrum. The substrate was cast iron with spherical graphite.
The coating had a thickness of 51.4 pm.
Fig. 3 shows the SEM micrograph of the surface.
Example 2: layer comprising nickel, molybdenum and phosphorus The following electrolyte composition was proposed:
510 g/I nickel sulphate hexahydrate - 20 g/I nickel chloride hexahydrate - 40 g/I boric acid - 21 g/I phosphorous acid - 50 g/I sodium citrate - 13 g/I molybdatophosphoric acid The chemicals are dissolved in order in warm water. After adding and dissolving all the components, the pH is adjusted. The pH is adjusted using 1% sodium hydroxide solution or 50% sulphuric acid.
The pH should lie between 1.2 - 3.0, the optimum is 2.3.
The electrolyte operates at a temperature of 45-55 C.
Deposition takes place whilst stirring moderately vigorously (300 -500 rpm).
A 1 mm thick brass plate having the dimensions 30 mm x 30 mm was used as the substrate.
A unipolar rectangular pulse was used to produce the layer, wherein the mean current density was 3.0 A/dm2. The cathodic current densities were 2.5 and 5.0 A/dm2 for 10 ms, the subsequent pulse pause was 10 ms.
The coating time was one hour.
The layers thus produced had the following composition:
nickel 96.2 wt.%, molybdenum 0.8 wt.% and phosphorus 3 wt.%, the alloy elements together gave 100%.
Date Recue/Date Received 2022-08-02 The layers showed good adhesion, were free from cracks and shiny, layer thicknesses were approximately 10 pm. Annealing at 200 C was carried out for 30 minutes.
Fig. 4 shows the scanning electron micrograph of the surface of the layer and the EDX
spectrum.
Example 3: layer comprising nickel, tin, molybdenum and phosphorus The following electrolyte composition was proposed:
510 g/I nickel sulphate hexahydrate - 20 g/I nickel chloride hexahydrate - 40 g/I boric acid - 21 g/I phosphorous acid - 50 g/I sodium citrate - 13 g/I molybdatophosphoric acid - 12 g/I tin (VI) chloride hydrate The chemicals are dissolved in order in warm water. After adding and dissolving all the components, the pH is adjusted. The pH is adjusted using 1% sodium hydroxide solution or 50% sulphuric acid.
The pH should lie between 1.2 - 3.0, the optimum is 2.3.
The electrolyte operates at a temperature of 55-75 C.
Deposition takes place whilst stirring moderately to vigorously (300 -500 rpm).
A 1 mm thick brass plate having the dimensions 30 mm x 30 mm was used as the substrate.
A bipolar rectangular pulse was used to produce the layer, wherein the mean current density was 2.3 A/dm2. The cathodic current densities were 2.0 and 6.0 A/dm2 for 20 and ms, the anodic current density was 5 A/dm2 for 5 ms, the subsequent pulse pause was 10 ms.
The coating time was one hour.
The layers thus produced had the following composition:
Date Recue/Date Received 2022-08-02 nickel 91.5 wt.%, molybdenum 2 wt.%, tin 0.5 wt.% and phosphorus 6 wt.%, the alloy elements together gave 100 %.
The layers showed good adhesion, were free from cracks and shiny. The layer thickness was approximately 10 pm.
Example 4: layer comprising nickel, molybdenum and phosphorus The following electrolyte composition was proposed:
340 g/I nickel sulphate hexahydrate - 20 g/I nickel chloride hexahydrate - 13.7 g/I sodium hypophosphite - 50 g/I sodium citrate - 2.5 g/I sodium molybdate The chemicals are dissolved in order in warm water. After adding and dissolving all the components, the pH is adjusted. The pH is adjusted using 1% sodium hydroxide solution or 50% sulphuric acid. The pH should lie between 5.0-5.2, the optimum is 5.1.
The electrolyte operates at a temperature of 45-55 C.
Deposition takes place whilst stirring moderately vigorously (300 -500 rpm).
A 1 mm thick brass plate having the dimensions 30 mm x 30 mm was used as the substrate.
A unipolar rectangular pulse was used to produce the layer, wherein the mean current density was 1.6 A/dm2. The cathodic current densities were 1.5 and 2.5 A/dm2 for 10 ms, the subsequent pulse pause was 10 ms.
The coating time was one hour.
The layers thus produced had the following composition:
nickel 90.5 wt.%, molybdenum 5.0 wt.% and phosphorus 4.5 wt.%, the alloy elements together gave 100%.
The layers showed good adhesion, were free from cracks and shiny.
Date Recue/Date Received 2022-08-02 Fig. 5 shows the surface of the layer in a scanning electron micrograph and the EDX
spectrum.
In particular the invention relates to a coating of metal surfaces of functional parts made of metal, preferably baking plates, wherein at least one coating with an alloy is applied galvanically to the metal surface. The functional parts can also be other metal parts which are used to heat food, such as frying pans, grill surfaces, cooking pots and the like. The baking plates are preferably baking plates for the industrial production of wafer products. All these functional parts are subsequently designated as baking plates.
Optionally it is provided that the coating comprises a surface layer which consists of a galvanically applied alloy which contains nickel, phosphorus, and tin as the main component and that the surface layer is an alloy layer obtained by a pulsed deposition, preferably an inverse pulsed deposition from a galvanic bath.
Only be using pulsed deposition, preferably an inverse pulsed deposition, can a coating be obtained on a metal surface which meets the high requirements, in particular in the food area. In particular, a coating is obtained which can be used in the food area, in particular in the baking industry, whilst adhering to the specification and conditions valid there. Optionally due to the properties of the pulsed method, it is also possible to influence or adjust the surface layer in terms of its properties.
Optionally it is provided that the surface layer contains phosphorus in the range of 1 to 15 wt.%, tin up to 10 wt.% and the remainder to 100 wt.% nickel.
Optionally it is provided that the alloy contains 0.05 to 10.0 wt.% tin and 1 to 15 wt.%
phosphorus and nickel to 100 wt.%.
By adding tin and/or phosphorus, the release of nickel from the coating can be reduced, in particular substantially prevented. Only with the coating according to the invention is it possible to meet the high requirements, in particular the high requirements in the food area. Differently configured layers cannot prevent the release of coating components, in Date Recue/Date Received 2022-08-02 particular nickel, and therefore do not meet the high requirements. Optionally it is provided that the phosphorus content in the surface layer lies in the range from 7 to 14%, in particular 9 to 12%. Optionally the release of nickel cannot be sufficiently prevented below a phosphorus content of 9%.
Optionally it is provided that the surface layer additionally contains molybdenum and that the surface layer contains up to 10 wt.% of molybdenum and/or that the alloy contains 0.01 to 10 wt.% of molybdenum.
Since the surface layer also contains molybdenum, the wear resistance of the coating, in particular the hardness of the coating can be increased.
Optionally it is provided that the surface layer has a roughness, the Ra value of which is less than 5 pm, preferably less than 3 pm and particularly preferably less than 2 pm.
Optionally it is provided that the layer thickness of the surface layer is at least 5 pm preferably between 10 pm and 50 pm.
Optionally it is provided that one or more underlayers are disposed between surface layer and metal surface.
Optionally it is provided that the underlayers are nickel layers applied electrolytically or without external current.
Optionally it is provided that the hardness gradient of the underlayers as far as the surface layer is configured to be ascending.
Optionally it is provided that the underlayers are double-layer and a first underlayer nearest the metal surface consists of a semi-gloss nickel layer or copper and a second underlayer consists of a gloss nickel layer.
Date Recue/Date Received 2022-08-02 In particular, the invention relates to a baking plate having a coating according to the invention, wherein the coated metal surface is the baking surface of a baking plate, in particular a baking plate for the industrial manufacture of crispy brittle wafer sheets, waffles and hollow wafers as well as baked products of all kinds.
Optionally it is provided that the baking surface is formed with a moulding forming the baking mould and engraving.
Optionally it is provided that the coated baking plate is annealed at temperatures between 150 C and 700 C, preferably between 200 and 400 C, particularly preferably at 300 C and that the coated baking plate is annealed for a duration in the range from one hour to six hours, preferably up to four hours.
Optionally it is provided that the baking plate body of the baking plate consists of cast iron, steel, aluminium, aluminium alloys or copper and alloys thereof such as brass.
In particular, the invention relates to a method for the coating metal surfaces, in particular baking plates made of cast iron, steel, aluminium or aluminium alloys or copper and alloys thereof such as brass.
Optionally it is provided that the metal surface is coated at least in sections with a surface layer of NiSnP or NiSnMoP alloy in a galvanic method, preferably pulsed method and particularly preferably in an inverse pulsed method from a galvanic bath.
Optionally it is provided that the pulsed deposition of the coating from an electrolyte bath is carried out with the following parameter ranges:
a unipolar pulse sequence with pulse current density 0.5-15 A/dm2 cathodic pulse time 5- 100 ms off time 0.5 - 25 ms Optionally it is provided that a unipolar pulse sequence with base current and pulse pause as follows is used to produce the layer: pulse current density from 0.5 to 15 Date Recue/Date Received 2022-08-02 A/dm2, base current density from 0.1 to 8 A/dm2, cathodic pulse time from 5 to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
Optionally it is provided that a bipolar pulse with pulse pause as follows is used to produce the layer: cathodic pulse current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, pulse pause from 0.5 to 30 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the pulse pause.
Optionally it is provided that a bipolar pulse with a base current as follows is used to produce the layer: cathodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, cathodic base current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms, anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms, with a repetition rate of the cathodic sequence of 1 to 50 before the anodic pulse current.
Optionally it is provided that the electrolyte bath contains salts and acids selected from the following group:
a) nickel sulphate hexahyd rate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
c) tin (IV) chloride hydrate in the range of 1 - 40 g/I
d) tin (II) sulphate in the range of 1 - 30 g/I
e) tin (II) chloride dihydrate in the range of 1 - 40 WI
f) sodium molybdate dihydrate in the range of 1 - 30 g/I
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
k) phosphoric acid in the range of 1 - 5 g/I
I) sodium hypophosphite in the range of 5 -40 g/I
m)sodium gluconate in the range of 40 - 90 g/I
Date Recue/Date Received 2022-08-02 n) potassium sodium tartrate in the range of 10 - 50 g/I
Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
c) tin (IV) chloride hydrate in the range of 1 - 40 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
k) phosphoric acid in the range of 1 - 5 g/I
Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/1 i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
k) phosphoric acid in the range of 1 - 5 g/1 Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
f) sodium molybdate dihydrate in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 g/I
i) boric acid in the range of 25 - 45 g/I
1) sodium hypophosphite in the range of 5 - 40 g/I
Optionally it is provided that the electrolyte bath additionally contains the following constituents:
g) molybdatophosphoric acid in the range of 1 - 30 g/I
h) sodium citrate in the range of 1 - 90 WI
Date Recue/Date Received 2022-08-02 Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
d) tin (II) sulphate in the range of 1 - 30 g/I
e) tin (II) chloride dihydrate in the range of 1 - 40 g/I
f) sodium molybdate dihydrate in the range of 1 - 30 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
m)sodium gluconate in the range of 40 - 90 WI
n) potassium sodium tartrate in the range of 10 - 50 g/I
Optionally it is provided that the electrolyte bath contains the following constituents:
a) nickel sulphate hexahydrate in the range of 250 - 700 g/I
b) nickel chloride hexahydrate in the range of 5 - 50 g/I
d) tin (II) sulphate in the range of 1 - 30 g/I
e) tin (II) chloride dihydrate in the range of 1 - 40 WI
f) sodium molybdate dihydrate in the range of 1 - 30 g/I
i) boric acid in the range of 25 - 45 g/I
j) phosphorous acid in the range of 1 - 25 g/I
m)sodium gluconate in the range of 40 - 90 WI
n) potassium sodium tartrate in the range of 10 - 50 g/I
Optionally it is provided that the pH of the electrolyte bath is 1.0 to 5.5 and the bath temperature of the electrolyte bath is 25 C to 75 C.
Optionally it is provided that that the pH of the electrolyte bath is 1.0 to 1.5, in particular 1.1, 1.2 and 1.3. Optionally it is provided that the bath temperature is 55 C
to 65 C, in particular 60 C.
Optionally it is provided that the method comprises the following further steps:
- washing the coated metal surface, - optionally drying the coated metal surface, Date Recue/Date Received 2022-08-02 - annealing the coated metal surface for a time in the range from one hour to six hours, in particular four hours, at a temperature in the range of 100 C and C, preferably between 200 C and 400 C, particularly preferably 300 C.
Optionally it is provided that a coating having the hardness in the range of 400 Vickers and 800 Vickers, in particular 600 Vickers, is produced.
Optionally it is provided that the hardness of the coating is increased by annealing to 700 Vickers to 1000 Vickers, in particular 900 Vickers.
The hardness of the coating can be adjusted by annealing. Before the annealing step the coating possibly has a hardness of 400 to 800 Vickers, in particular 600 Vickers. The hardness of the coating can be increased by annealing to 700 Vickers to 1000 Vickers, in particular 900 Vickers. The hardness of the coating can be adjusted by the annealing time and also the annealing temperature. In particular, a lower hardness of the coating can be achieved by a short annealing time and/or by a low annealing temperature. The annealing can be carried out in an annealing device, in particular an annealing furnace.
The term annealing should be understood in this context as a general heating of a material over a longer time interval. The annealing process can be carried out in air or also in an inert furnace atmosphere.
Date Recue/Date Received 2022-08-02
Claims (21)
1. A
baking plate for the industrial manufacture of baked products, whereby a baking surface of the baking plate is provided with a moulding and an engraving, the moulding and engraving constituting the baking mould, and whereby the baking surface is a coated metal surface, wherein at least one coating comprising an alloy is applied galvanically to the metal surface from an electrolyte bath, wherein:
the coating comprises a surface layer which consists of a galvanically applied alloy which contains nickel, phosphorus and tin, wherein the alloy contains 0.05 to 10.0 wt. % tin and 1.0 to 15 wt. % phosphorus and the remainder up to 100 wt. % nickel, wherein the pH-value of the electrolyte bath is 1.0 to 5.5 and the bath temperature of the electrolyte bath is 25 C to 75 C, wherein the surface layer is an alloy layer obtained by pulsed deposition, wherein the surface layer has a roughness, the Ra value of which is less than 5 pm, wherein the surface layer is produced by:
a unipolar pulse sequence as follows:
pulse current density from 0.5 to 15 Aidm2;
cathodic pulse time from 5 to 100 ms; and off time from 0 to 25 ms, or the surface layer is produced by:
a bipolar pulse with a base current as follows:
Date recue/Date received 2023-03-27 cathodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms;
cathodic base current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms;
anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms;
with a repetition rate of the cathodic sequence of 1 to 50 before the anodic pulse current.
baking plate for the industrial manufacture of baked products, whereby a baking surface of the baking plate is provided with a moulding and an engraving, the moulding and engraving constituting the baking mould, and whereby the baking surface is a coated metal surface, wherein at least one coating comprising an alloy is applied galvanically to the metal surface from an electrolyte bath, wherein:
the coating comprises a surface layer which consists of a galvanically applied alloy which contains nickel, phosphorus and tin, wherein the alloy contains 0.05 to 10.0 wt. % tin and 1.0 to 15 wt. % phosphorus and the remainder up to 100 wt. % nickel, wherein the pH-value of the electrolyte bath is 1.0 to 5.5 and the bath temperature of the electrolyte bath is 25 C to 75 C, wherein the surface layer is an alloy layer obtained by pulsed deposition, wherein the surface layer has a roughness, the Ra value of which is less than 5 pm, wherein the surface layer is produced by:
a unipolar pulse sequence as follows:
pulse current density from 0.5 to 15 Aidm2;
cathodic pulse time from 5 to 100 ms; and off time from 0 to 25 ms, or the surface layer is produced by:
a bipolar pulse with a base current as follows:
Date recue/Date received 2023-03-27 cathodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms;
cathodic base current density from 0.5 to 12 A/dm2 with a pulse time from 5 to 100 ms;
anodic pulse current density from 0.5 to 20 A/dm2 with a pulse time from 5 to 100 ms;
with a repetition rate of the cathodic sequence of 1 to 50 before the anodic pulse current.
2. The baking plate according to claim 1, wherein the pulsed deposition is inverse pulsed deposition from a galvanic bath.
3. The baking plate according to claim 1 or 2, wherein the Ra value is less than 3 pm.
4. The baking plate according to claim 1 or 2, wherein the Ra value is less than 2 pm.
5. The baking plate according to any one of claims 1 to 4, wherein the surface layer additionally contains molybdenum.
6. The baking plate according to any one of claims 1 to 4, wherein the surface layer additionally contains molybdenum up to 10 wt. %.
7. The baking plate according to any one of claims 1 to 4, wherein the alloy additionally contains 0.01 to 10 wt. % molybdenum.
8. The baking plate according to any one of claims 1 to 7, wherein the layer thickness of the surface layer is at least 5 pm.
9. The baking plate according to any one of claims 1 to 7, wherein the layer thickness of the surface layer is between 10 pm and 50 pm.
Date recue/Date received 2023-03-27
Date recue/Date received 2023-03-27
10. The baking plate according to any one of claims 1 to 7, wherein one or more underlayers are disposed between the surface layer and the metal surface.
11. The baking plate according to any one of claims 1 to 10, wherein the one or more underlayers are nickel layers applied electrolytically or by electroless plating.
12. The baking plate according to claim 10, wherein the hardness gradient runs in an ascending manner from the metal surface to the surface layer.
13. The baking plate according to claim 10, wherein the one or more underlayers comprise two underlayers that are double-layer and a first of the two underlayers nearest the metal surface consists of a nickel layer or copper and a second of the two underlayers consists of a nickel layer.
14. The baking plate according to any one of claims 1 to 13, wherein the coated baking plate is annealed at a temperature between 150 C and 700 C
and the coated baking plate is tempered for a duration in the range of one hour to six hours.
and the coated baking plate is tempered for a duration in the range of one hour to six hours.
15. The baking plate according to any one of claims 1 to 14, wherein a baking plate body of the baking plate consists of cast iron, steel, aluminum, aluminum alloys, copper or copper alloys.
16. A method for making the baking plate according to any one of claims 1 to 15, wherein a metal substrate is coated with the surface layer via a pulsed method from a galvanic electrolyte bath.
17. The method according to claim 16, wherein the electrolyte bath contains salts and acids selected from the group consisting of:
a) nickel sulphate hexahydrate in the range of 250-700 g/I;
b) nickel chloride hexahydrate in the range of 5-50 g/l;
Date recue/Date received 2023-03-27 c) tin (IV) chloride hydrate in the range of 1-40 g/l;
d) tin (II) sulphate in the range of 1-30 g/l;
e) tin (II) chloride dihydrate in the range of 1-40 g/l;
f) sodium molybdate dihydrate in the range of 1-30 g/l;
g) molybdatophosphoric acid in the range of 1-30 WI;
h) sodium citrate in the range of 1-90 g/l;
i) boric acid in the range of 25-45 g/l;
j) phosphorous acid in the range of 1-25 g/l;
k) phosphoric acid in the range of 1-5 g/l;
l) sodium hypophosphite in the range of 5-40 g/l;
m) sodium gluconate in the range of 40-90 g/I ; and n) potassium sodium tartrate in the range of 10-50 g/l.
a) nickel sulphate hexahydrate in the range of 250-700 g/I;
b) nickel chloride hexahydrate in the range of 5-50 g/l;
Date recue/Date received 2023-03-27 c) tin (IV) chloride hydrate in the range of 1-40 g/l;
d) tin (II) sulphate in the range of 1-30 g/l;
e) tin (II) chloride dihydrate in the range of 1-40 g/l;
f) sodium molybdate dihydrate in the range of 1-30 g/l;
g) molybdatophosphoric acid in the range of 1-30 WI;
h) sodium citrate in the range of 1-90 g/l;
i) boric acid in the range of 25-45 g/l;
j) phosphorous acid in the range of 1-25 g/l;
k) phosphoric acid in the range of 1-5 g/l;
l) sodium hypophosphite in the range of 5-40 g/l;
m) sodium gluconate in the range of 40-90 g/I ; and n) potassium sodium tartrate in the range of 10-50 g/l.
18. The method according to claim 16, comprising the further following steps:
washing the coated metal surface, annealing the coated metal surface for a time in the range from one hour to six hours, at a temperature in the range of 100 C and 700 C.
washing the coated metal surface, annealing the coated metal surface for a time in the range from one hour to six hours, at a temperature in the range of 100 C and 700 C.
19. The method according to claim 18 further comprising drying the coated metal surface after washing the coated metal surface.
20. The method according to claim 17, wherein the coating has a hardness in the range of 400 Vickers and 800 Vickers.
21. The method according to claim 18 or 19, wherein the coating after annealing is 700 to 1000 Vickers.
Date recue/Date received 2023-03-27
Date recue/Date received 2023-03-27
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP16168257.0 | 2016-05-04 | ||
| EP16168257.0A EP3241929A1 (en) | 2016-05-04 | 2016-05-04 | Coating of functional parts from metal |
| PCT/EP2017/060622 WO2017191240A1 (en) | 2016-05-04 | 2017-05-04 | Coating for functional parts made of metal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA3022885A1 CA3022885A1 (en) | 2017-11-09 |
| CA3022885C true CA3022885C (en) | 2023-10-03 |
Family
ID=55913501
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA3022885A Active CA3022885C (en) | 2016-05-04 | 2017-05-04 | Coating of functional parts made of metal |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US11350635B2 (en) |
| EP (2) | EP3241929A1 (en) |
| CN (1) | CN109415833B (en) |
| BR (1) | BR112018072363B1 (en) |
| CA (1) | CA3022885C (en) |
| RU (1) | RU2710148C1 (en) |
| WO (1) | WO2017191240A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6909582B2 (en) * | 2017-01-18 | 2021-07-28 | 株式会社Ｊｃｕ | Coloring plating solution and coloring method |
| CN110029379A (en) * | 2019-05-05 | 2019-07-19 | 东莞市康圣精密合金材料有限公司 | Ultra-wide stainless steel materials nickel plating appearance optimization technique |
| CN115038817A (en) * | 2020-03-03 | 2022-09-09 | 日本制铁株式会社 | Ni-plated steel sheet and method for producing same |
| KR20240093443A (en) * | 2021-06-18 | 2024-06-24 | 맥스터리얼, 인크. | Process of producing coated surfaces, coatings and articles using them |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5565389A (en) * | 1978-11-09 | 1980-05-16 | Toshiba Corp | Forming method of black alloy plating film for selective absorption of solar heat |
| JPS6314888A (en) * | 1986-07-04 | 1988-01-22 | Nippon Dento Kogyo Kk | Method for plating gray sn-ni alloy |
| JP2757673B2 (en) * | 1992-03-19 | 1998-05-25 | 上村工業株式会社 | Continuous plating method of electroless Ni-P-Mo |
| KR970000190B1 (en) * | 1993-06-02 | 1997-01-06 | 니홍고오깡 가부시키가이샤 | Method for producing zinc coated steel sheet |
| JPH07143840A (en) * | 1993-11-25 | 1995-06-06 | Hiroshi Imamura | Tray for bread baking |
| JPH08119645A (en) * | 1994-10-27 | 1996-05-14 | Asahi Glass Co Ltd | Mold for glass formation and formation of glass product for cathode-ray tube |
| US5614003A (en) * | 1996-02-26 | 1997-03-25 | Mallory, Jr.; Glenn O. | Method for producing electroless polyalloys |
| JP3283233B2 (en) * | 1998-06-26 | 2002-05-20 | 荏原ユージライト株式会社 | Alloy plating method and plated product with excellent corrosion resistance |
| RU2126776C1 (en) | 1998-07-16 | 1999-02-27 | Закрытое акционерное общество "ЭТНА" | Raw meal for fire-protective heat-insulation boards and method of manufacture thereof |
| CN101545105A (en) * | 2009-05-05 | 2009-09-30 | 天津大学 | Method for preparing high wear-resistant nickel-tin-phosphorus composite plating layer and plating bath |
| JP5365928B2 (en) * | 2009-12-28 | 2013-12-11 | 有限会社プロトニクス研究所 | High corrosion resistance Ni-based composite plating film |
| CN102787329A (en) * | 2012-08-31 | 2012-11-21 | 重庆大学 | Preparation method of efficient Ni-Mo-P/Ni hydrogen evolution electrode |
-
2016
- 2016-05-04 EP EP16168257.0A patent/EP3241929A1/en not_active Withdrawn
-
2017
- 2017-05-04 WO PCT/EP2017/060622 patent/WO2017191240A1/en unknown
- 2017-05-04 EP EP17721378.2A patent/EP3452641A1/en active Pending
- 2017-05-04 US US16/098,556 patent/US11350635B2/en active Active
- 2017-05-04 CN CN201780041548.2A patent/CN109415833B/en active Active
- 2017-05-04 BR BR112018072363-0A patent/BR112018072363B1/en active IP Right Grant
- 2017-05-04 CA CA3022885A patent/CA3022885C/en active Active
- 2017-05-04 RU RU2018140030A patent/RU2710148C1/en active
Also Published As
| Publication number | Publication date |
|---|---|
| BR112018072363A2 (en) | 2019-02-19 |
| EP3452641A1 (en) | 2019-03-13 |
| CA3022885A1 (en) | 2017-11-09 |
| CN109415833A (en) | 2019-03-01 |
| WO2017191240A1 (en) | 2017-11-09 |
| BR112018072363B1 (en) | 2023-01-31 |
| US20190230939A1 (en) | 2019-08-01 |
| CN109415833B (en) | 2021-11-09 |
| RU2710148C1 (en) | 2019-12-24 |
| EP3241929A1 (en) | 2017-11-08 |
| US11350635B2 (en) | 2022-06-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA3022885C (en) | Coating of functional parts made of metal | |
| JP6576832B2 (en) | Method for producing a chromium coating on a metal substrate and coated article | |
| CN102181861B (en) | Method for surface treatment of metal alloy | |
| CN105189828A (en) | Nickel chromium nanolaminate coating having high hardness | |
| JP3715743B2 (en) | Manufacturing method of Mg alloy member | |
| JP5894721B2 (en) | Surface-treated metal plate and method for producing molded product using the surface-treated metal plate | |
| JP6224086B2 (en) | Method for obtaining a cooking vessel with an anodized and electrochemically colored outer surface | |
| JP2002348699A (en) | Plated film and coated article therewith | |
| US20100143622A1 (en) | Process for providing aluminium cookware with a copper coating | |
| JP2014095097A (en) | Method for producing trivalent chromium plated-molded article and trivalent chromium-plated molded article | |
| CN102953101A (en) | Chrome plated zinc alloy zipper and electroplating method thereof | |
| JP2015024625A (en) | Molding die for production method thereof | |
| KR101451507B1 (en) | The manufacture of non-stick frying pan and non-stick frying pan prepared by | |
| KR102031902B1 (en) | Ceramic coated kitchen container for induction heating and method for manufacturing the same | |
| JP6220394B2 (en) | Manufacturing method for manufacturing cookware articles having a silver or silver alloy inner surface obtained by electroforming | |
| US2738897A (en) | Tin plate baking pan | |
| US20050218004A1 (en) | Process for making a composite aluminum article | |
| JP4579706B2 (en) | Articles with improved zinc erosion resistance | |
| CN115137215A (en) | Cooker and method for manufacturing the same | |
| CN105586582A (en) | Base layer of non-stick product coating and manufacturing method thereof | |
| CN104080375A (en) | Method for obtaining cooking vessel having colored hard anodized outer face | |
| KR100382284B1 (en) | Coloring method process for magnesium compound | |
| CN115772691A (en) | Cooking utensil | |
| KR0146874B1 (en) | Method for manufacturing zn-cr/zn alloy coated steel sheet with 2-layers | |
| Jol | Coating with Metals and Inorganic Materials |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request |
Effective date: 20210617 |
|
| EEER | Examination request |
Effective date: 20210617 |
|
| EEER | Examination request |
Effective date: 20210617 |
|
| EEER | Examination request |
Effective date: 20210617 |
|
| EEER | Examination request |
Effective date: 20210617 |
|
| EEER | Examination request |
Effective date: 20210617 |
|
| EEER | Examination request |
Effective date: 20210617 |
|
| EEER | Examination request |
Effective date: 20210617 |